Springfield police said Monday they are investigating a suspicious death on the east side of town.

Lt. Tony Vienhage with the Springfield Police Department said officers were dispatched to the 400 block of South Patterson Avenue on Monday morning after a neighbor saw a man slumped over the steering wheel of a pickup truck.

Vienhage said officers responded to the scene and found a deceased man in his 40s inside the truck.

Vienhage declined to discuss the specifics of how the man died, but said there are some circumstances that cause police to consider the death suspicious.

The scene is near the O'Reilly Automotive corporate offices.

A spokesman for the police department said more information would be released later in the day.